Commercially available hydroxypropylmethylcelluloses contain 19-30 weight-% methoxy content and 4-32 weight-% hydroxypropyl content and are known as Methocel cellulose ethers (Dow Chemical Co.). Ethylcellulose and sodium carboxymethylcellulose are also well known and readily available.
Methocel has been used in the prepartion of buccal or sublingual products for transmucosally acting medicaments, as described in British Pat. No. 1,171,691 and 1,279,214 and U.S. Pat. No. 3,870,790. Methocel has been considered to be lacking in the most desirable properties for making compressed long lasting troches and as a result dry skim milk powder combined with Guar gum has been substituted (U.S. Pat. No. 3,590,117). Carboxypolymethylene and sodium caseinate have also been used for the same purpose (U.S. Pat. No. 3,594,467). While it is known that buccal or sublingual lozenges and tablets intended to be swallowed can be made with various active agents and carriers, where steady prolonged medication is required and a regular rate of release is needed with good absorption of medicament, no fully satisfactory carrier has been heretofore been produced. The present invention is directed toward improvements in a carrier base for use in the preparation of orally buccaly or sublingually etc. administered lozenges and tablets as well as suppositories which have a regular and prolonged release pattern for a systemically absorbable medicament or active ingredient incorporated therein.